This invention relates to an improved continuous ore reaction process. While other ore reaction processes are known, they appear to have one or more deficiencies. Benefits of the process of this invention and some of the deficiencies of prior art processes which are overcome with the process of this invention include:
(1) the ability to operate efficiently and economically at pressures in excess of atmospheric, PA1 (2) the ability to remove efficiently and economically fine particles of ore which are part of the ore introduced into the process or which are generated during the process, PA1 (3) the ability to cool rapidly the ore slurry exiting the process and to retard flow of liquid reagent out of the process, PA1 (4) the ability to operate efficiently and economically on a continuous basis, PA1 (5) the ability to operate without any moving parts in the reactor such as paddle blades or stirring mechanisms requiring complex sealing mechanisms, all of which would be subject to excessive corrosion and erosion, especially at elevated temperatures and pressures, PA1 (6) the ability to construct the reactor of acid resistant brick, rather than expensive metals or alloys, because there are no moving parts, and PA1 (7) the ability to calculate optimum fluidization for carrying out an optimum reaction process. PA1 (8) the ability to achieve a staging effect of a counter-current stirred tank leaching reactor. PA1 (a) providing an upper and lower chamber for the vertical column, each of said chambers having a bottom outlet with a diameter which is less than that of the diameter of the chamber; PA1 (b) maintaining sufficient upward flow of liquid reagent in the upper chamber so that the particulate ore is wetted and deaerated, at least some fine particles thereof are carried overhead for removal, and the remainder thereof settle and enter the lower chamber, PA1 (c) maintaining sufficient fluidization and retention time in the lower chamber so that the desired amount of reaction with the ore takes place, at least some of the fine ore particles which are generated from the reaction process and/or which are introduced with the particulate ore are entrained and carried upward for removal, and the reacted particulate ore exits the lower chamber. PA1 (a) providing an upper and lower chamber for the vertical column, each of said chambers having a bottom outlet with a diameter which is less than that of the diameter of the chamber; PA1 (b) maintaining sufficient upward flow of acid in the upper chamber so that the particulate ore is wetted and deaerated, at least some fine particles thereof are carried overhead for removal, and the remainder thereof settle and enter the lower chamber; PA1 (c) maintaining sufficient fluidization and retention time in the lower chamber so that the desired amount of impurities are leached from the particulate ore, at least some of the fine ore particles which are generated from the leaching process and/or which are introduced with the particulate ore are entrained and carried upward for removal, and the leached particulate ore exits the lower chamber. PA1 X=the fluidization index PA1 L=the liquid upflow rate PA1 S=the solid downflow rate PA1 Gmf=the minimum fluidization velocity for a bed of solids from which no solids are withdrawn PA1 P.sub.1 =the liquid density PA1 P.sub.S =the solid density PA1 E=the void fraction at the design condition.
It should be noted that items (5) and (6) are important because at elevated temperatures, and especially above about 150.degree. C., only expensive metals and alloys resist attack by acid. Thus, the process of this invention permits the construction of a reactor system which both can operate at high temperatures and can utilize inexpensive materials of construction. Similarly, item (3) is important because it permits the use of inexpensive materials of construction downstream of the reactor to receive the reacted ore.